Telephone coupling device



Sept. 10, 1940. A. G. cooLEY'" TELEPHONE COUPLING, DEVICE Filed Jan. 27, 194p ii" i Patented Sept. 10, 1940 2.214.090, runrnomi COUPLING nnvroi Austin G. Cooley, New York-N. Y., assignor to i Wide World Photos, Ina, NewIork, N. Y., a corporation of New York I Application January 21, m, No. 315,905, l8 (cl. 119-2)- This invention-relates. to transmission systems and more particularly to systems-of transmission employing telephone facilities as the transmission medium or as a connecting link be- 5 tween twopoints.

An object of the invention is to provide an improved coupling arrangement whereby signal apparatus may be coupled to a telephone line'or the like by electromagnetic induction to the ear- 10 piece or sound reproducer of the usual .subscribers telephoneset.

In certain of the more recent types of subscriber's telephone sets, the magnet-diaphragm system is built as a separable unit from the rest 15 of the set so that the magnetic coils and diaphragm are rea telephone set. As an example of such construction, reference may "be hadto the Western Electric type F1 telephone hand set. I have discovered 20 that with the newer types of hand sets such as the Western Electric type F1,'a more eflicient coupling is achieved by 'a specially designed' coupling unit. Accordingly, it is another object of this invention to provide an improved coupling de- 5 vice for coupling a signalling mechanism electromagnetically to the earpiece of a telephone hand set of the Frenc phone type and more Fs'pecially of the Western Electric Fl type. v

A feature of the invention relates-to an im- 80 proved coupling device which is readily attachable to the earpiece of a telephone hand set, and which enables the signals to be induced-more efficiently into, or received from. a telephone line.

, Another feature relates to' an improved cou- 35 pling device which is provided with a special form of mounting and locking framewhereby the device may be firmly attached to the earpiece of I a telephone set without danger of scratching or a otherwise marring the earpiece. As a result of this feature, the proper location of the, magnets of the coupling device may-be readily secured, and'once ascertained are eifectively locked in position on the telephone receiver.

45 A further feature relates to a novel construction of telephone coupling device which can be used alternatively as a coupling unit to atele'- phone'set or as an impedance adjusting or matching transformer.

A further feature relates to the novel mm...

' tion, arrangement and relative location of parts constituting an improved arrangement for coupling signal apparatus to a telephone line with- 5 out physical or conductive'connection the wires dily removable as a unit from the the hand set on its support.

thereofland without-disturbing the normal operation of the'telephone plant or equipment.

Other features and advantages not specifically enumerated will be apparent after a consideration of the following detailed descriptions and 5 I the appended claims.

Referring to the drawing, r Fig. l is a perspective view showing the-coupling device according to the invention attached to the earpiece of a subscriber's telephone hand 10 set. I

Fig. 2 is a sectionalview of Fig. 1 taken along the line 2-2 thereof and viewed in the direction of the arrows. Fig. 3 isa side elevational view of the coupling unit according to the invention.-

Fig. 4 is a schematic wiring diagram showing the manner in which the coupling device is used to couple to a telephone line: v

Fig. 5 is an end view of the magnetic system of the telephone receiver of Fig. 2.

Referring to Fig. 1, there is shown in perspective a typical telephone hand set designated generally by the numeral i. As shown, the set is of the "French" phone type comprising a mouthpiece 2 and microphone housing 3 at one end, and an earpiece and sound reproducing portion 4 at the other end, both the earpiece andmouthpiece portions beingunited by a yoke portion Ii. The electrical connections to the microphone and earpiece are made by the usual flexible conductor 6 which is connected into the telephone system in angconventional way, for example as shown in I Fig. 4. It will be understood of course that the hand set of Fig. 1 is normally supported on a switch hook assembly (not shown) whereby the continuity of the circuitfrom the hand set to the telephone line'or telephone exchange is controlled by the removal from, or replacement of While the invention is usablewith any telephone hand set of the so-called French type, it is particularly eflicient in connection with a tion I, the rim of'which is externally threaded to receive the internally threaded earpiece-cover 8.

' Cover 8 is provided with a plurality of openings 8, to allow the sound waves to emerge,- The wall of member I is provided with an annular shoulder ill on which is seated the sound reproducing unit conslstingof the bar magnets H with their upwardly projecting pole pieces l2, IS. on which are mounted the magnet coils or windings M, II.

, must be specially designed with The reproducing unit also includes a sound reproducing diaphragm it which is clamped or restrained around its periphery in any well-known manner, the diaphragm and its clamping supports being enclosed within an annular metal rim or ferrule I! so that all the parts i I to it form a compact unitary assembly. Fastened to the bottom of this assembly is an insulator strip I8 carrying a central contact stud l9 and a. surrounding annular contact ring 20 which are connected respectively to the terminals of the magnet windings Id, I5. Fastened interiorly to the bottom of bowl d are two leaf springs 2|, 22, which are adapted to engage resiliently the respective contacts It and 26, thus allowing the sound reproducing unit to be turned through any angle around its vertical axis without disturbing the electrical connections to the magnet winding. Springs 2i and 22 areconnected to the conductors of cord 6 carrying the sound currents to be reproduced. In this type of hand set; the parts 3, d and 5, are molded from a suitable non-magnetic or insulating material.

I have found that sign of the sound reproducing unit in this type of hand set, there is a preferable position for the electromagnetic coupling unit, and this unit respect to the positional location of the electromagnetic system of the reproducer. In accordance with this invention, the coupling unit which is designated generally in-Fig..3 by numeral 28, comprises a U-shaped laminated magnetic core 2%, the vertical legs of which are preferably tapered at their ends 25, 26. Ihave found that the best results are obtained by shaping the poles 26, 27!, and arranging the dimensions of the U-shaped core so that the'said poles are directed towards the ends of the bar magnets H which polarize the pole pieces l2, l8. Supported on each of the legs 27 are two sets of windings 28, wand 30, 3!. windings 28, 29, are the main inducing or coupling windings and 'are preferably of a large number of turns and are connected in series with the supply conductors 32, 33, the signal device-which is to be coupled to the line 6. windings 30, 3|, are insulated from windings 28, 28, in any'suitable manner. The windings 30, 3|, are preferably of few turns and are connected in series to the respective plugin prongs 34, 35, mounted on the insulator block 36. In order to protect the windings and at the leading to or from same time to prevent scratching of the telephone hand set, the tapered pole pieces 25 and 28 are enclosed in suitable fibre sheaths 31 having their outer surfaces smooth. The sheaths 31 may be fastened in any suitable manner on the core legs.

' After the two sets of windings have been mounted on the core and connected in the manner shown in Fig. 2, the core and windings are enclosed within a metal housing 38 of suitable material such as aluminum, brass or the like. The space within the housing may, if desired, be filled with a suitable insulating compound 39. which upon hardening, rigidly holds the core in place. The housing as will be seen in Figs. 1 and 2 is generally U-shaped so as to enable the unit to be fitted'again'st the bottom of the bowl portion 1 with the rib l clearing the face ll of the housing. In order to attach the coupling unit to the earpiece 4 so that it will not become loose, as

a result of accidental Jars or the like, there is carried by the housing 38, a spring frame 42 which becausep'f the special de-.

portion 44 of the frame 42 by means of suitable vrivets'tti is a shallow dish-shaped metal member 46 preferably having its undersurface provided with a coating B1 of felt or other sound deaden-.

erably the dimensions of the coupling unit are so arranged that the tapered poles 25 and 26 are somewhat below the magnet windings it, l5 and the bowed portions of the spring frame 62 are so designed that in order to fit the portion '36 into the earpiece cover 8, the bowed portions of the spring frame 32 can be sprung to elongate the frame to enable'it to be turned around the studs as thus clearing the top of the receiver earpiece. Thereupon the spring frame contracts lengthwise whereby the member 46 is firmly held against the earpiece cover 8.

Preferably, the device is mounted on the receiver so that the field of force between the poles '25, 26, is directed towards the polarizing bar telephone on a table or other similar support to prevent the telephone tilting or rolling on said support.

Referring to Fig. 4, there is shown diagram matically the circuit-connections when the device is used to couple to a telephone line. In this figure, the parts corresponding to those of Figs. 1 to 3, have the same designation numerals. The block 50 represents any well-known form of signal generator, for example a facsimile transmitting machine of any well-known type such for example as represented in my prior Patent No. 2,015,742, whereby the lights and shades of a picture or the like are translated into a correspondingly modulated audio frequency altemating current, for example of approximately 1800 C. P. S. The output of the machine may be impressed on a terminal amplifier 5| and then through a reversing switch 52 as described in Paterit No. 2,179,445,. and thence to the windings 28, 29 (Fig. 2). The signals are therefore induced into the magnet coilsof the earpiece 4 and are thence impressed on the telephone line L through the subscriber's terminal equipment which usually includes a condenser 53 and the switch hook contacts 54. Under these circumstances therefore, the signal generator 50 is coupled to the telephone line L without any physical connection thereto, it being understood of course that in order to complete the connection to the line, the telephone hand set is removed from its switch hook and the telephone connection to the desired receiving point 55 is completed in the usual manner of completion of a telephone call. At the receiving station 55, there may be a picture reproducing machine of any well-known type, such phone line throughthe intermediary of the tele- 3 cases however,- it may be desirable to impress the signals on a telephone line without using the telephone earpiece, for exampie'as shown in Fig. 4, the line Li may be another telephone line having connected thereto at the transmitting end a coupling transformer 56'. The coupling tacts 51, I8, which are connected to the 10' and ll.

device 23 may under these circumstances, be used as an impedance adjusting or matching transformer by removing it from the earpiece 4 and connecting the prongs 3'4, 35, into the conprimary Under these circumthe generator 50 are of the transformer 56.

stances, the signals from,

, impressed upon the windings 28, 29, which act as the primary of a coupling transformer, the secondary of which is formed of the windings As above described, the turns ratio of the respective windings 28-29, 30-, may be telephone line Ll.

said telephone receiver.

designed to achieve the required impedance transformation between the amplifier 5i and the A similar coupling unit acting as an impedance matching transformer'may be used at the receiving station 55.

While certain specific embodiments have been described,. it will be understood that various changes' and modifications may be made therein without departing from the spirit and scope of the invention. g

What I claim.is:-

1. A device of the character described comprising a magnetic core, means to energize said core in accordance with signals, and means to attach said core to a telephone service receiver of the typehaving a bowl-shaped. portion closed by a perforated earpiece, the last-mentioned means including a member adapted to fit against the'earpiece of the receiver and resilient means connecting said member to said core whereby said core is firmly held against the bowlportion of the receiver.

2. -A device according to claim 1 in which said resilient means comprises "a spring connection between the core and said member. 1

3. Adevice according to claim lin which said resilient means'includes a frame having bowed spring arms.

, 4. A device according to claim 1 in which said member is dish-shaped in form and is adapted to at in the concave portion of the earpiece of 5. An electromagnetic coupling device for attachment-to the earpiece of a telephone service set comprising a magnetic core having a pair of poles arranged to be positioned in spaced relation to the magnetic system of the telephone receiver but offset laterally with respect to said 5 system, and a resilient frame for attaching said core to said receiver, said frame carrying a membet/fitted within the earpiece of the receiver..

.6. An electromagnetic coupling device according to'claim' 5 in which the said member which.

is fitted within the earpiece is perforated to allow the sound waves from the telephone receiver to emerge.

'7. A coupling device of the character described comprising a magnetic core, means to removablyattach'said core to a telephone service instrument, asignal source, an inducing winding on said core energized from said signal source, and

preferably the auxiliary another winding on said core insulated from said inducing winding, both said windings being designed to act as an impedance adjusting transformer between signalling lines.

8. An electromagnetic coupling device for coupling signalling mechanism to a telephone line comprising a magnetic core, apair of windings on said core, one of said windings designed for coupling said signal mechanism to the telephone line by induction through the magnetic system of the telephone receiver, the other of said windings being proportioned with respect to the first winding to act as an impedance adjusting transformer for cou'plinga signal. device to the line independently of the magnetic. system of a telephone receiver. f

9. A coupling device of the character described comprising a magnetic core, means to removably attach said core to a telephone service instrument, .2. main inducing winding on said core energized by signals, and-- an auxiliary winding on said core insulatedfrom the said inducing winding, both's'aid windings coacting with said core to constitute an impedance matching transformer.

10. A device of the character described com-' prising a pair of separate transformer windings, individual connector terminals for said windings,

' a magnetic core for said windings, and means an electromagnetic coupling unit having a magnetic core and energizing winding therefor for coupling asignal device to themagnetic system of said earpiece, the last-mentioned means including a resilient frame adapted to surround said bowl portion to maintain said unit in'adjusted position with respect thereto, with the ends of said core held firmly againstthe wall of said bowl-shaped portion.

12. An electromagnetic coupling unit of the character described, comprising a U-shaped ma netic core, the legs of said core having tapered poles, a winding on each leg, means to removably attach said unit to the earpiece of a telephone hand set of the French" type, the lastmentionedmeans including a frame for maintaining said tapered poles in engagement with ,said earpiece.

13. A coupling unit according to claim 12 in which said tapered poles are provided with an outer protective sheath of smooth hard mate rial suchas flbre.

14. A coupling unit of the character'described' comprising a u shaped magnetic core, a .winding on said core, a housing'enclosing said core and winding, means to removably attach said housing to a telephone service instrument, and a pair of plug-in contact prongs insulatingly carried by said housing, said prongs being connected to said winding.

' 15. A coupling device for coupling a signal mechanism inductively to a line through a sound reproducer of the type having at least one polarizing magnet and a pair 'of pole-pieces'extending transversely thereto, said device comprising a magnetic core having a pole, means to support said core so that said pole is oflset laterally with respect to both pole pieces but is directed mainly towards said polarizingmagnet, and means to energize said core under control of said signal mechanism.

16. A coupling device for coupling a signal mechanism inductively to a line through a sound reproducer of the type having a permanent magnet disposed in one plane and an electro-magnetic pole member extending transversely thereto towards the sound reproducing diaphragm, said device comprising a magnetic core having pole pieces, and means to removably fasten said device to said reproducer so that said permanent magnet is located between the pole piece of the coupling device and the pole piece of the reproducer.

17.An arrangement for coupling a signal mechanism to a line comprising a sound reproducer having a vibratory diaphragm with a permanent magnet mounted beneath and parallel to one face thereof, a coupling device comprising a magnetic core with polar ends energized under control of said mechanism, and means to mountsaid device on said reproducer so that said polar ends are also disposed beneath the said face 01 said diaphragm and with, said polar ends di-, rected' towards said permanent magnet.

18. An arrangement according to claim 17 in which said reproducer is providedwith a pairof spaced. permanent'bar magnets and said device is mounted on said reproducer so that the polar ends thereof are directed towards the ends of said bar magnets.

AUSTSIN 'G. cooimr; v 

